Moving bin sorting apparatus

ABSTRACT

This invention relates to a sorting apparatus for receiving sheets from a copying machine. A plurality of tray members receive the sheets as the tray members move past a sheet discharge zone. The drive rotates cam members to move the tray members vertically as sheets are moved along the sheet path towards the tray members. The cam members are formed with variable pitch camming surfaces such that the tray members are in close proximity to each other except when positioned adjacent to the sheet discharge zone, whereupon the camming surfaces affect a spreading movement of the trays upon passing the sheet discharge zone.

United States Patent Stemmlc MOVING BIN SORTING APPARATUS [75] Inventor: Denis J. Stemmle, Williamson, NY.

[73] Assignee: Xerox Corporation, Stamford,

Conn.

[22] Filed: Dec. 29, 1972 [21] Appl. No.: 319,957

[52] US. Cl. 271/64, 270/58 [51] Int. Cl 1365b 31/24 [58] Field of Search 271/64, 158, 88; 270/58 [56] References Cited UNITED STATES PATENTS 2,335,078 11/1943 Osborn 27l/l58 X 3,561,754 2/l97l Gaffron et al. 27l/64 X 3,721,435 3/1973 Zanders 271/64 Primary ExaminerEvon C. Blunk Assistant Examiner-Bruce H. Stoner, Jr. Attorney, Agent, or Firm-James J. Ralabate et al.

[57] ABSTRACT This invention relates to a sorting apparatus for receiving sheets from a copying machine. A plurality of tray members receive the sheets as the tray members move past a sheet discharge zone. The drive rotates cam members to move the tray members vertically as sheets are moved along the sheet path towards the tray members. The cam members are formed with variable pitch camming surfaces such that the tray members are in close proximity to each other except when positioned adjacent to the sheet discharge zone, whereupon the camming surfaces affect a spreading movement of the trays upon passing the sheet discharge zone.

6 Claims, 9 Drawing Figures PATENTED JAN 2 9 I974 SHEET 1 BF 6 FIG.

PATENTED JAN 2 9 I974 SHEET 2 BF 6 PATENTEU JAN 2 9 H174 SHEU 5 OF 6 MOVING BIN SORTING APPARATUS This invention relates to apparatus for sorting copies advanced from a copier/duplicator into collated sets.

In copier/duplicator systems there has been a growing concern for the distribution and handling of the copy sheets in a collated fashion. In the past, sorting systems included large and bulky sorting bin modular units with a multitude of trays arranged for movement relative to the sheet path for increased storage as de scribed in US. Pat. No. 3,356,362. Another approach for the sorter has been a rotating housing carrying bins or trays past a copy sheet path as described in US. Pat. No. 2,876,008, 2,951,697, and 3,076,647. While this construction is satisfactory in one sense, there are certain disadvantages such as the number of trays that can be accommodated as well as the number of sheets in each tray. Still another sorter design is a vertically moving distributor in the form of trays moved up and down together as described in U. S. Pat. No. 3,561,754. While this type of construction is suitable for some applications, it is not entirely satisfactory for many copier/duplicators in commercial use.

The present invention is, generally speaking, a moving bin or tray sorter/collator adapted for universal usage with copier/duplicators of all types. Moreover, the arrangement of the bins or trays and the manner in which they receive copy sheets enables a highly reliable copier sorter/collator system for rapid distribution of copy sheets in collated sets.

It is therefore a general object of this invention to improve distribution of copy sheets.

It is another object of this invention to enable the distribution of copy sheets in collated sets in a reliable manner.

It is still a further object of the invention to enhance the delivery of copy sheets to a moving bin sorting apparatus.

It is still a further object of the invention to achieve sorting of copy sheets into a moving tray configuration which is simple and compact to construction.

It is still a further object of the invention to reduce significantly the level of noise normally associated with the sorting of sheet material.

The above and added advantages of the present invention will be more apparent after reading the following detailed description which refers to accompanying drawings in which:

FIG. 1 is a perspective view of a high speed copier/- duplicator system including a sorter/collator apparatus according to the present invention.

FIG. 2 is a schematic view illustrating the xerographic components of the copier/duplicator system;

FIG. 3 is an elevation view of the tray assemblies of the sorter/collator apparatus;

FIG. 4 is a plan view of a tray assembly of the sorter/- collator apparatus;

FIG. 5 (a)-(c) are exploded views of the tray assemblies illustrating details of the opening tray operation;

FIG. 6 is an isometric view of the drive assembly for the sorter/collator apparatus, and

FIG. 7 is an exploded view of the tray assemblies illustrating set separation upon unloading.

FIG. 1 shows a copier/duplicator system generally designated 2 including a copier machine 3, whch is a high speed copier/duplicator capable of producing simplex or duplex copies at the option of a machine operator. The copier machine 3 has a platen 4 for receiving documents to be reproduced, and a control panel 5 which includes various control knobs, buttons, and switches for selecting various modes of operation such as simplex and duplex copies and the number of copies to be reproduced. In accordance with the invention, the copier/duplicator system includes a sorting apparatus 6 having tray assemblies 7.

As best shown in FIG. 2, the copier/duplicator system includes an automatic xerographic apparatus which includes a photosensitive plate including a photoconductive layer 10 that is placed over a conductive backing. The plate is formed in the shape of a drum 11 and the drum mounted upon a shaft 12 that is journaled for rotation in the machine frame. Basically, the xerographic drum is rotated in the direction indicated so as to pass sequentially through a series of xerographic processing stations. The photosensitive drum and the xerographic processing apparatus are driven at predetermined speeds relative to each other from a drive system (not shown) and the operations thereof coordinated in order to produce proper cooperation of the various processing mechanisms.

The original, to be reproduced, is placed upon a transparent horizontally supported platen 4 and the original scanned by means of a moving optical scanning system and to produce a flowing light image of the original. The scanning system includes an elongated horizontal extended aperture lamp 15 and a movable lens element 18. The lamp and lens element moves in coordination across the object supported upon the platen to focus successive incremental bans of illumination reflected from the object onto the moving drum surface at synchronous speeds therewith. The optical path is folded by means of a pair of image mirrors 19 and 20 interposed between the lens and the drum surface, the drum is first uniformly charged by means of a corona generator 13 positioned in charging station A. Under the influence of the flowing light image, the uniformly charged photoconductive surface is selectively dissipated in the non-image areas to form what is commonly known as a latent electrostatic image.

The latent electrostatic image is carried on the drum surface from the exposure station into the developing station C. The developing station primarily is comprised of a developer housing 22 adapted to support a supply of two-component developer material 21 therein. The developer material is transported by means of a bucket system 23 from the bottom of the developer housing to an elevated position where the material is delivered into the active development zone. The developer material is caused to flow downwardly in contact with the upwardly moving drum surface under closely controlled conditions wherein charged toner particles are attracted from the developer mix into the image areas on the plate surface thus making the image visible.

The moving drum surface next transports the developed xerographic image to a transfer station D. Cut sheets of final support material are also moved into the transfer station, the backside of the copy sheet is sprayed with an ion discharge from a transfer corotron 25 inducing on the sheet a charge having a polarity and magnitude sufficient to attract the toner material from the drum surface to the final support material. The induced charge also electrostatically tacks the final support material to the drum surface. In order to remove the copy sheet from the drum surface, a stripper finger 28 is positioned downstream from the transfer corotron. The finger is arranged to move between the drum surface and the copy sheet and lifts the sheet from the drum surface and the copy sheet is directed along a predetermined path of travel into contact with a stationary vacuum transport 29.

Although a preponderance of the toner material is transferred from the drum surface to the copy sheet during the transfer process, invariably some residual toner remains behind on the drum surface after transfer. This residual toner is transported on the drum surface after transfer. The residual toner is transported on the drum surface into a cleaning station E where it is brought under the influence of cleaning corotron 30 adapted to neutralize the electrostatic charge tending to hold the residual toner to the drum surface. The neutralized toner is mechanically cleaned from the drum surface by means of a brush or the like and the toner collected within a housing 31. A conveyor moving in an endless loop through tubes 32 transport the collected residual toner back to the developer housing where it is deposited within the developer mix so that it can be once again reused in the xerographic developing process.

The copy sheet, which has been removed from the drum surface after the transfer operation, is moved along stationary transport 29 into fusing station E. The fuser 33 is basically made up of an upper fuser roll 34 and a lower fuser roll 35 mounted in operative relation to each other and arranged to coact so as to support a sheet of materialin pressure driving contact therebetween. The lower roll is heated. As the heated roll is rotated in the direction indicated, the heated surface of the lower roll is pressed into intimate contact with the image face of the support sheet. Mechanical and heat energy transported from the roll surface to the support sheet to permanently bond the toner particles to the support material.

Upon leaving the fuser, the fixed copy sheet is passed through a curvalinear sheet guide system, generally referred to as into cooperating advancing rolls 43 and 44. At this point, depending on the mode of operation selected, the copy sheet is either forwarded directly to the sorter or into the upper supply tray 52 by means of a movable sheet guide 45 before entering the sorter.

It is believed that the foregoing description is sufficient for purposes of the present application to show the general operation of a xerographic reproducing machine. For a more detailed explanation of the copier/- duplicator xerographic components reference is made to U.S. Pat. No. 3,645,615, entitled Copying Apparatus.

SORTING APPARATUS Sorter apparatus 6 comprises a horizontal vacuum transport assembly 103 which receives copy sheets from the copier/duplicator and advances them to a plurality of tray assemblies 7. A drive apparatus moves the tray assemblies vertically intermittently for receiving copy sheets advanced along the transport path as will be explained hereinafter. A drive motor 111 serves to drive transport assembly 103 which uses vacuum generated by a pump 108.

The tray assemblies 7 are arranged in groups of approximately five trays each for purposes of multiple bin unloading as will become more apparent. Each of the tray assemblies has a tray portion 205 which is inclined at an angle of approximately 20 to the horizontal and an end portion 207 which is perpendicular to the tray .portion 205 and then extends in a horizontal direction at tail portion 209. Tray portion 205 and tail porton 209 are mounted on cam followers which engage the spiral slot formed in the cylindrical surface of cam members to be described.

Tail portion 209 has a cam follower mounted 213 which includes a spring member 215 for enabling movement of the cam follower 213 relative to the tray assembly 203. Tray portion 205 has a pair of cam followers 211 mounted adjacent the leading comers thereof and received in spiral grooves 221 of camming members 223 and 224 positioned at opposite sides of the entrance to the tray assembly. A third cam member 225 which has spiral portions 227 for receiving cam follower 213. By this arrangement, a three point suspension is provided by the tray assemblies.

Each of the cam members 223 and 224 at the entrance of the tray assemblies and cam member 225 at the rear of the tray assemblies have the same path. The path has a series of fine closely spaced or low pitch surfaces 231 separated by a high pitch surface 233 providing separation of the tray assemblies into groups to enable multiple bin unloading. It will be noted that by this arrangement that multiple bin unloading results in copy sets in adjacent tray assemblies being offset about A inch such that set separations of sets or books is effected upon simultaneous unloading of a group of the tray assemblies (FIG. 7). Also by the above arrangement, the tray assemblies compact in sapce in a series of nested arrangements, to enable getting a large number of trays into a confined area.

At the vicinity of sheets entering the sorter is a very I high pitch portion 235. The construction of the cam members 223, 224, and 225 with pitch portion 235, renders an opening tray or bin feature as each of the tray assemblies passes the horizontal transport which moves the copy sheets into each of the tray assemblies. By this structure, as the tray assemblies pass the horizontal transport, there is an opening movement between the tray assemblies greatly facilitating receipt of copy sheets into them. The tray assemblies then close to the normal gap from the previous tray assembly. It has been found that this opening bin feature, makes less difficult the movement of the copy sheets, into the moving tray assemblies, even where large stacks of paper are received in the tray assemblies to enable a reliable trouble free operation. At the same time, by virtue of the sorter construction, a great number of tray assemblies can be used in a relatively small area. Moreover, the construction of the cam members enables receiving a high volume of sheets in a tray assembly.

The drive mechanism for moving the tray assemblies vertically includes a drive motor 250 which drives three timing belts 251, one each for the cam members 223, 224, and 225. Torque is transmitted to each of the cam members by a pulley associated with each of the cam members by a pulley associated with each of the timing belts 251. The cam members may be made out of any suitable material such as Delrin, a trademark of Du- Pont Corporation, Wilmington, Del. The drive motor 250, is energized intermittently by electrical signals supplied by machine control when sheets on transport assembly are detected by a lamp and photocell sensing unit 253 with the aid of a reflector 255 (FIG. 6.).

In operation a plurality of switches 258 serve to determine the location of the tray assemblies relative to the sheet discharge zone by contacting tray tab portions 259 (FIG. 4). which serve as a tray coding device. Switches 258 supply a signal to machine control to indicate tray assemblies are in a ready condition to receive sheets and also to indicate when drive motor 250 should reverse. Another function of the switches is to prevent the tray assemblies from over indexing beyond the normal range by supplying a signal to machine control.

One or more switches 256 are mounted near cam member 223 to control de-energization of motor 250 upon a single revolution of the cam member. In this manner the tray assemblies advance together with each tray assembly receiving a sheet in the discharge zones. Limit switches 257 are provided as a backup to detect the upper and lower limits of the path of the tray assemblies to de-energize the motor 250 to prevent damage in the event of component failure.

By the above described moving tray apparatus the distribution of copy sheets from a reproduction machine is .greatly enhanced. Thus the reliability of stacking the sheets in collated identifiable fashion is most apparent. It will be appreciated that this improved sorting apparatus greatly facilitates the sorting and stacking of sheets distributed by copier/duplicator systems into collated sets.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. Sorting apparatus comprising:

a frame,

a plurality of vertically extending cam members sup ported by said frame,

a vertically extending array of closely spaced tray members supported by said cam members,

drive means for rotating said cam members to move said tray members vertically,

transport means for moving sheets towards a sheet discharge zone adjacent to the path of the moving tray members,

said cam members being formed with a low pitch spiral camming surface and a high pitch spiral camming surface,

said high pitch spiral camming surface being positioned adjacent to the sheet discharge zone to effeet a spreading movement between tray members upon passing said discharge zone.

2. Apparatus according to claim 1 wherein at least one of said cam members has camming means thereon to actuate switching means coupled to said drive means to de-energize said drive means to effect stopping movement of said tray members for a time sufficient to receive a sheet into a one of said tray members.

3. Apparatus according to claim 2 including a sensing means positioned along said transport means coupled to said drive means to energzie said drive means to ad vance the tray members.

4. Apparatus according to claim 1 wherein said drive means is reversible and switching means operative to reverse direction of said drive means at predetermined intervals.

5. Apparatus according to claim 1 wherein said cam members are formed with a medium pitch camming surface positioned intermedaite said low pitch camming surface to effect separated groupings of trays.

6. In a reproduction system in which copy sheets are reproduced from documents and distributed for sorting into trays, an improved tray sorting apparatus for sorting copy sheets into collated sets, comprising a frame,

a plurality of vertically extending cam members supported by said frame,

a vertically extending array of closely spaced tray members supported by said cam members,

drive means for rotating said cam members to move said tray members vertically,

transport means for moving sheets towards a sheet discharge zone adjacent to the path of the moving tray members,

said cam members being formed with a low pitch spiral camming surface and a high pitch spiral camming surface,

said high pitch spiral camming surface being positioned adjacent to the sheet discharge zone to effect a spreading movement between tray members upon passing said discharge zone. 

1. Sorting apparatus comprising: a frame, a plurality of vertically extending cam members supported by said frame, a vertically extending array of closely spaced tray members supported by said cam members, drive means for rotating said cam members to move said tray members vertically, transport means for moving sheets towards a sheet discharge zone adjacent to the path of the moving tray members, said cam members being formed with a low pitch spiral camming surface and a high pitch spiral camming surface, said high pitch spiral camming surface being positioned adjacent to the sheet discharge zone to effect a spreading movement between tray members upon passing said discharge zone.
 2. Apparatus according to claim 1 wherein at least one of said cam members has camming means thereon to actuate switching means coupled to said drive means to de-energize said drive means to effect stopping movement of said tray members for a time sufficient to receive a sheet into a one of said tray members.
 3. Apparatus according to claim 2 including a sensing means positioned along said transport means coupled to said drive means to energzie said drive means to advance the tray members.
 4. Apparatus according to claim 1 wherein said drive means is reversible and switching means operative to reverse direction of said drive means at predetermined intervals.
 5. Apparatus according to claim 1 wherein said cam members are formed with a medium pitch camming surface positioned intermedaite said low pitch camming surface to effect separated groupings of trays.
 6. In a reproduction system in which copy sheets are reproduced from documents and distributed for sorting into trays, an improved tray sorting apparatus for sorting copy sheets into collated sets, comprising a frame, a plurality of vertically extending cam members supported by said frame, a vertically extending array of closely spaced tray members supported by said cam members, drive means for rotating said cam members to move said tray members vertically, transport means for moving sheets towards a sheet discharge zone adjacent to the path of the moving tray members, said cam members being formed with a low pitch spiral camming surface and a high pitch spiral camming surface, said high pitch spiral camming surface being positioned adjacent to the sheet discharge zone to effect a spreading movement between tray members upon passing said discharge zone. 